The issue of planned housing developments is making the contests for two seats on the Marin Board of Supervisors the hottest tickets on Marin's Tuesday ballot.

There will be several higher-level contests on the ballot when Marin voters go to the polls. Candidates for the 2nd District congressional seat, the District 2 state Senate seat, and the District 10 state Assembly seat are competing in primaries to determine who will face off in the November election.

But for Susan Adams and Judy Arnold, the two incumbent supervisors facing challenges from candidates who have questioned their past support for higher-density housing along transportation corridors, Tuesday is decision day.

San Rafael Councilman Damon Connolly is trying to unseat Adams while Novato realty agent Toni Shroyer is vying with Arnold. The Adams/Connolly match-up has garnered the most attention, however, perhaps because Adams had to fend off a recall effort launched by housing opponents last fall.

"I think it is one of the more intriguing local races going on in Northern California," said David McCuan, a Sonoma State University associate professor of political science.

McCuan said the housing issue provided Connolly with a "huge opening."

"What Connolly has been able to do is run to scare tactics, and those scare tactics have made this race competitive," McCuan said.

With a little more than a week before the election, Connolly sent out a mailer accusing Adams of throwing schools "under the bus" by supporting a project that could result in the creation of 72 affordable housing units at Marinwood Plaza, a derelict strip mall. The piece features a picture of young children boarding a school bus.

"It's a completely unfair portrayal," Adams said. "It further fans the flames using misinformation about nonprofit housing programs in Marin. We have a number of them and they're not ruining schools."

Connolly said, "My campaign has been factual and issue based and that includes my mail."

Brian Sobel, a Petaluma-based political analyst, said that if Connolly can define Adams as being for high-density, infill housing it will give him an advantage.

"Despite all the talk about the vision of high density," Sobel said, "at the end of the day that becomes a very tough argument to sell to people in suburbia."

McCuan said that if either Adams or Arnold loses, it could be a watershed moment in Marin politics. McCuan said, "It could threaten the other supervisors moving into the next election. There is a lot at stake."

The races for the District 2 state Senate seat and the District 10 state Assembly seat have taken a back seat primarily because one candidate in each of those contests has dominated fundraising.

Mike McGuire, a member of the Sonoma County Board of Supervisors, holds a commanding lead over his three opponents: Lawrence Wiesner of Santa Rosa, a certified public accountant; Harry Lehman, a Novato lawyer; and Derek Knell, general manager of Strahm Communications in San Rafael.

Assemblyman Marc Levine, D-San Rafael, has opened up a similarly large lead over his four challengers: Marin Community College District trustee Diane Conti, Santa Rosa Councilwoman Erin Carlstrom, Greg Allen, a Novato high-tech recruiter; and Veronica Jacobi, a former Santa Rosa councilwoman. Jacobi, whose name will appear on the ballot, has dropped out of the race and endorsed Conti.

McCuan and Sobel say the contest in these races will be for second place; but they see little possibility of an upset victory by any second-place finisher in November.

Even less likely, pundits say, is that Rep. Jared Huffman, D-San Rafael, will be unseated in November. In Tuesday's primary, Huffman's only challengers are two Garberville residents, Andy Caffrey, an environmental activist, and Dale Mensing, a supermarket cashier. Caffrey, a Democrat, was among the dozen candidates who ran for the 2nd District seat two years ago, when Huffman was first elected to Congress. This is the first time that Mensing, a Republican, has run for office.

Voters in the Ross Valley Sanitary District, where the board just approved a five-year schedule of rate increases, will have their pick of five candidates to fill three seats. The candidates include incumbent Pam Meigs and four challengers. Thomas Gaffney of Ross, a municipal finance consultant with a master's degree from the University of California at Berkeley, and Michael Boorstein of Kentfield, a computer systems consultant, voiced their support for the rate hike. The other two candidates: Joseph Descala of San Anselmo, a semi-retired lawyer, and Rick Holland, a Realtor with Bradley Real Estate, opposed it.

Marin voters will weigh in on six ballot measures that would benefit local school districts, add more funding to local libraries and create a permanent home for the Marin County Farmers Markets.

The polls will be open from 7 a.m. to 8 p.m. on Tuesday, election day. Absentee ballots may be turned in at the polls or at the elections office at the Marin Civic Center, 3501 Civic Center Drive, Room 121, San Rafael. Voters may call 415-473-6456 for help or visit www.marinvotes.org for more information.